Last ride 76 

Norman, I just noticed that you are in Manila. (I can be somewhat slow at times.) Mostly locations don't affect things much. This time, I am going to venture it does. I said before I thought it looked possibly like "student" work. Now I'm going to guess, local enthusiast. Bet almost anything. The small size of the frame forces the head lugs to intersect. I have read professional frame builders, noting how difficult it is to make that conjunction smoothly, there are so many factors at play. The Philippines in general, and Manila specifically, has a very active and inventive welding industry, from Jeepneys to commercial and domestic custom fabrication, there is an abundance of skilled artisans who work with metal. I think this frame was the work of one such.
It would explain the bottom bracket, and lug details. The builder was referencing a Colnago, not trying to truly make a "fake". I hope you are not disappointed, by my guess, I think you have something pretty unique on your hands. There may even be a way to trace it back to the builder. Take a look at my recent track bike thread regarding who may have built it. Someone may remember the guy who loved bikes.
Best regards, Eric